By Dr. Mercola
First, itís important to understand that vitamin D3 is an oil soluble steroid hormone. Itís formed when your skin is exposed to ultraviolet B (UVB) radiation from the sun (or a safe tanning bed). When UVB strikes the surface of your skin, your skin converts a cholesterol derivative in your skin into vitamin D3.
However, the vitamin D3 that is formed is on the surface of your skin does not immediately penetrate into your bloodstream. It actually needs to be absorbed from the surface of your skin into your bloodstream.
The critical question then is: how long does it take the vitamin D3 to penetrate your skin and reach your bloodstream?
If youíre thinking about an hour or two, like I did until recently, youíre wrong. Because new evidence shows it takes up to 48 hours before you absorb the majority of the vitamin D that was generated by exposing your skin to the sun!
Therefore, if you shower with soap, you will simply wash away much of the vitamin D3 your skin generated, and decrease the benefits of your sun exposure. So to optimize your vitamin D level, you need to delay washing your body with soap for about two full days after sun exposure.
Now not many people are not going to bathe for two full days.
However you really only need to use soap underneath your arms and your groin area. , so this is not a major hygiene issue. Youíll just want to avoid soaping up the larger areas of your body that were exposed to the sun.
Other Reasons to Avoid the Shower
Avoiding the shower can also benefit your health in a number of other ways, because unless you have well water, youíre showering in water from a municipal water supply that is loaded with chlorine,fluoride, disinfection by products, and pharmaceutical drugs that have made their way into the sewer system.
Chlorine, although itís best avoided as much as possible, is actually not the major issue. The biggest danger comes from the byproducts created when chlorine combines with organic material in the water.